In general, a vacuum transfer system is a system in which an object is grabbed by negative pressure generated in such a way that a vacuum pump is operated by compressed air with highly rapid speed and thus inside air of a suction cup or pad is sucked, so as to transfer the object to a predetermined location. The present invention relates to a vacuum pump of the vacuum transfer system. More particularly, the present invention relates to an ejector as an important component of the vacuum pump.
An example of a conventional ejector and a vacuum pump are disclosed in Korean Utility Model Registration No. 274370. Referring to FIG. 1, this vacuum pump 1 includes: a housing 2 having an inlet chamber C1, a vacuum chamber C2, and a discharge chamber C3; and an ejector 3 having a plurality of nozzles 4a, 4b, and 4c mounted on partition walls W between the chambers C1, C2, and C3. Usually, the plurality of nozzles 4a, 4b, and 4c are multi-stage nozzles disposed in series.
A vacuum transfer system is configured such that the vacuum pump 1 is fixed to a structure by using a bracket supporting the housing 2, and is configured to include a suction cup 5 connected to the vacuum chamber C2 so as to communicate with an inside of the ejector 3, and a robot arm connected to the suction cup 5.
In the vacuum transfer system, compressed air is supplied to the inlet chamber C1, rapidly passes through the plurality of nozzles 4a, 4b, and 4c of the ejector 3 in sequence, and is discharged outwards via the discharge chamber C3. At this time, inside air of the suction cup 5 is introduced into the ejector 3 so as to be discharged with the compressed air. In this discharge process, a vacuum and negative pressure are generated in inner space of the suction cup 5, and an object is grabbed by the negative pressure so as to be transferred to a predetermined location.
Although this type of vacuum pump 1 is utilized in the field at present, it is problematic in that the ejector 3 cannot be individually utilized. That is, the housing 2 requires a frame and partition walls W so as to install the nozzles 4a, 4b, and 4c in the housing 2, and by means of this, the ejector 3 may be installed.
To overcome this problem, a vacuum ejector pump is disclosed in Korean Patents Nos. 393434 (the same as U.S. Pat. No. 6,394,760), 578540, and 629994. FIG. 2 illustrates a vacuum pump 6 disclosed in Korean Patent No. 393434. In the vacuum pump 6, an individually structured cartridge-type cylindrical ejector 8 is disclosed. Further, the ejector 8 is detachably provided in the housing 7.
Although the ejector 8 is individually and detachably provided, however, in the same manner as FIG. 1, the housing 7 also requires inlet, vacuum, and discharge chambers C1, C2, and C3, and partition walls W between the chambers C1, C2, and C3 so as to install the ejector 8. Furthermore, the above-described components of the housing 7 should be accurately designed according to characteristics of the ejector 8.
Accordingly, it is problematic in that the ejector 8 is ineffective in being mounted and utilized. Furthermore, it is also problematic in that the ejector 8 is ineffective in assembling and manufacturing the entire vacuum pump 6 including the housing 7.